A search for rare B → Dμ$^{+}$μ$^{−}$ decays

arXiv (Cornell University)

Abstract

A search for rare $B \rightarrow D \mu^+ \mu^-$ decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb$^{-1}$. No significant signals are observed in the non-resonant $\mu^+\mu^-$ modes, and upper limits of $\mathcal{B}(B^0 \rightarrow \overline{D}^0 \mu^+ \mu^-) < 5.1 \times 10^{-8}$, $\mathcal{B}(B^+ \rightarrow D_s^+ \mu^+ \mu^-) < 3.2 \times 10^{-8}$, $\mathcal{B}(B_s^0 \rightarrow \overline{D}^0 \mu^+ \mu^-) < 1.6 \times 10^{-7}$ and $f_c/f_u \cdot \mathcal{B}(B_c^+ \rightarrow D_s^+ \mu^+ \mu^-) < 9.6 \times 10^{-8}$ are set at the 95\% confidence level, where $f_c$ and $f_u$ are the fragmentation fractions of a $B$ meson with a $c$ and $u$ quark respectively in proton-proton collisions. Each result is either the first such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a $J/\psi \rightarrow \mu^+ \mu^-$ decay. The branching fraction of $B_c^+ \rightarrow D_s^+ J/\psi$ multiplied by the fragmentation-fraction ratio is measured to be $f_c/f_u \cdot \mathcal{B}(B_c^+ \rightarrow D_s^+ J/\psi ) = (1.63 \pm 0.15 \pm 0.13) \times 10^{-5}$, where the first uncertainty is statistical and the second systematic.

Authors 18

1. C. Agapopoulou
2. C. Aidala

   Laboratoire de Physique de Clermont Auvergne

   Affiliation as printed

   LPC - Laboratoire de Physique de Clermont (Campus Universitaire des Cézeaux, 4 Avenue Blaise Pascal, TSA 60026, CS 6002, 63178 Aubière Cedex - France)

3. S. Akar
4. R. Amalric
5. S. Amato
6. D. Ao
7. A. Bailly-reyre
8. J. M. Basels Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen

9. K. Belous
10. I. Belyaev

    Centre de physique des particules de Marseille

    Affiliation as printed

    CPPM - Centre de Physique des Particules de Marseille (163, avenue de Luminy - Case 902 - 13288 Marseille cedex 09 - France)

11. G. Bencivenni

    Laboratoire de Physique Nucléaire et de Hautes Énergies

    Affiliation as printed

    LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies (Barre 12-22, 1er étage 4 Place Jussieu 75252 Paris Cedex 05 - France)

12. E. Ben-Haim
13. Alexander Berezhnoy
14. Ia. Bezshyiko
15. P. Billoir
16. Alice Biolchini
17. M. Birch
18. A. Bizzeti